C语言面试题

#include <stdio.h>

int main()
{
    int a[5] = {1, 2, 3, 4, 5};
    int* p1 = (int*)(&a + 1); // <==> (unsigned int)&a+sizeof(*&a) => 整个数组后面的那个地址
    int* p2 = (int*)((int)a + 1); <=> 取a[0]后三个字节拼接a[1]第一个字节 => 0x02000000
    int* p3 = (int*)(a + 1); <=> a[2]
    
    printf("%d\n", p1[-1]); // (unsigned int)p1-1*sizeof(*p1) => a[4]
    printf("%d\n", p2[0]);  //  0x02000000
    printf("%d\n", p3[1]); // a[3]
    
    return 0;
}